[Samba] Debug file_new then open_file_ntcreate fails with doesn't exist

[Matthew Schumacher]

On 7/16/21 1:44 PM, Matthew Schumacher via samba wrote:
> On 7/16/21 12:12 PM, Jeremy Allison wrote:
>>>
>>> Anybody see this before or thoughts on work arounds?  I'm running 
>>> the latest stable samba 4.14.6 in AD mode.
>>
>> We haven't seen that, it looks strange. I take it there's no
>> other application running that could race and delete ?
>>
>> Can you check the recently release 4.15.rc1 to see if it's
>> something that got fixed ? There have been *lots* of changes
>> in the pathname area between 4.14.x -> 4.15.rc1.
>
> I isolated it to make sure there wasn't a race and checked with 
> smbstatus to ensure nothing else is using the share.
>
> Looks like the same issue with 4.15rc1  The create was called at 
> 12:23:28.127137 and the open at 12:23:28.129007 which is only 2ms apart.
>
> Since the samba process to service both requests is the same, it 
> doesn't seem like it's a samba issue, perhaps the filesystem is slow?  
> The samba server is virtualized in qemu.
>
> Any suggestions on other stuff to look at will be helpful.

Tried a few more things:

     strict sync = yes
     sync always = yes
     aio max threads = 1


Still get the same issue:

[2021/07/16 13:07:54.393693,  5, pid=2001, effective(1000, 10000), 
real(1000, 0)] ../../source3/smbd/dosmode.c:183(unix_mode)
   unix_mode: unix_mode(PartShare/partlib/DB2017/ReadOnlyMode.ini) 
returning 0660
[2021/07/16 13:07:54.393702, 10, pid=2001, effective(1000, 10000), 
real(1000, 0)] ../../source3/smbd/open.c:3530(open_file_ntcreate)
   open_file_ntcreate: fname=PartShare/partlib/DB2017/ReadOnlyMode.ini, 
dos_attrs=0x0 access_mask=0x80 share_access=0x7 create_disposition = 0x1 
create_options=0x200000 unix mode=0660 oplock_request=0 private_flags = 0x0
[2021/07/16 13:07:54.393712,  5, pid=2001, effective(1000, 10000), 
real(1000, 0)] ../../source3/smbd/open.c:3608(open_file_ntcreate)
   open_file_ntcreate: FILE_OPEN requested for file 
PartShare/partlib/DB2017/ReadOnlyMode.ini and file doesn't exist.
[2021/07/16 13:07:54.393735, 10, pid=2001, effective(1000, 10000), 
real(1000, 0)] ../../source3/smbd/open.c:6056(create_file_unixpath)
   create_file_unixpath: NT_STATUS_OBJECT_NAME_NOT_FOUND